Employee Brent Gill poses a question while playing the part of a customer during a Black Friday rehearsal at a Best Buy store in Denver. Employees practiced Black Friday scenarios, managing crowds and organizing lines.

The shoppers stream in, unrelenting. Store clerks bravely hold their positions and get hit with a barrage of questions. Why don’t I see the Galaxy S4? Will you match this price on the iPad 2? Where’s the bathroom?

Pandemonium, and it’s not even Black Friday yet.

But this pandemonium is planned. It’s dress-rehearsal day at Best Buy. The shoppers actually are store employees, doing their best to rattle colleagues stationed behind cash registers.

After all, if you can’t deal with 130 co-workers creating faux havoc, how are you going to survive the real masses swarming in to kick off the holiday-season buying spree at 6 p.m. Thanksgiving?

The Best Buy rehearsal is part team-building rah-rah, part play-acting and all caffeine-fueled mayhem for a couple of hours early Saturday morning prior to regular opening time.

Bleary-eyed workers begin arriving around 7:30 a.m. at store No. 211 at South Colorado Boulevard and East Mexico Avenue. Most are wearing Best Buy’s regulation blue polo shirt. Almost all carry either take-out coffee cups or canned energy drinks.

At 8 a.m., store manager Doug Ryan assembles the team near the home-theater section. He starts a round of rhythmic clapping.

“How many here have not worked Black Friday before?” he asks.

About a third of the employees raise their hands.

“Black Friday, in my opinion, is the funnest day at Best Buy,” he says. “The energy of the customers coming into the store, the fact they are choosing us — it’s a special atmosphere.”

Ryan goes over the rehearsal agenda. After the introductory talk, employees split into their respective departments for detailed briefings on door-buster items, pricing, inventories and how best to pitch extended-warranty protection and store credit cards.

Then comes the main event. Department manager Kevin Ribbens describes it as “bum rushing” individual departments with dozens of workers playing frantic customers posing endless questions — sometimes with an element of impatience.

“Where’s the line for the 60-inch Samsung?”

“It’s over there, sir.”

“But somebody told me to come over here!”

“No, sir, it’s over there.”

Best Buy last year opened stores at midnight for Black Friday. This year marks the first time that its stores will open Thanksgiving evening.

A poll released Monday by the University of Connecticut shows that although more stores than ever are opening to shoppers on Thanksgiving Day this year, nine of every 10 respondents said they don’t plan to spend the holiday shopping for bargains.

Just 7 percent of adults said they plan to visit stores on Thanksgiving Day. Forty-nine percent said they disapprove of the retail movement to open stores on Thursday.